When making an electrical cable having at least one wire including a conductor and an insulation surrounding said conductor and when combining said wires to a cable it is very important to make sure that the insulation fulfills certain mechanical and electrical properties. For example, the insulation materials need to be selected such that environmental influences like very low or very high temperatures or humidity do not change the insulation properties to such an extent that a short circuit would arise.
Furthermore, in buildings or installations where increased safety requirements must be satisfied the cables must be fire-resistant. Every country has established certain industrial standards which must be fulfilled by such cables in this respect. For example, according to the German Industrial Standard (DIN Deutsche Industrie-Norm) 4102 Section 12 cables and wires must sustain temperatures up to 1000° C. over a period of up to 90 minutes according to a unit temperature time curve. During this time a voltage of 400 Volt is applied to the cables and wires and the cables and wires only pass this burn test if no short circuit or conductor interruption occurs.